Radio apparatus for aircraft



Aug. 22, 1950 A. w. FAULKNER 2,519,553

RADIO APPARATUS FOR AIRCRAFT Filed Sept. 24. 1948 2 Sheets-Sheet 1 &

THERMAL SWITCH 32 \NVfiN A g- 1950 A. w. FAULKNER 2,519,553

RADIO APPARATUS FOR AIRCRAFT Filed Sept. 24, 1948 2 Sheets-Sheet 2RECORDINQPRODUCING OBLITERATING HEAD oau'rERATlNc HEAD HEAD ELE CTROELECTRO MAGNET MAGNET I I 35 i 7.

RECORDING AND REPRODUCING HEAD Q QJECMM Ma DWLJ J g. ATTVE Patented Aug.22, 1950 UNITED STATES OF atlases RADIO APPARATUS FQR AIRCRAFT ArundellFaulkner, Woking, England Application-September 24, 1948, SerialNo.51,1129 "In Great Britain N Member-'27, 119456 1 Claim. '1

This invention is concerned with emergency radio apparatus for use insummoning assistance to aircraft which have crashed unobserved bypersons on the ground, the apparatu comprising a unit capable of beingjettisoned from the aircraft and provided with a signal record and aradio transmitter for transmitting the recorded signal automaticallyafter the unit has been jettisoned.

-An object of this invention is to give a reasonable chance that, whenan aircraft has been forced down and possibly seriously damaged, S O Ssignals indicating approximately its positionwill 'be transmitted *for aconsiderable period after the accident, irrespective of whether themachine has alighted on land or water.

Embodiments of the invention will now be described, by way of example,with reference to the accompanying diagrammatic drawings, in which:

Fig. 1 is a cross-sectional elevation of .a recording and transmittingunit to be jettisoned located :in a spring-loaded catapult device,

Fig. 2 is :a cross-sectional plan of the embodiment taken at 2--2 inFig. 1,

Fig. .3 is'a sketch illustrating the recording :and transmitting unit ofFig. 1 descending by means of a parachute after being jettisoned by thecatapult device of Fig. .1,

Fig. 4 is a sketch of recording apparatus suitable for use in theembodiment of Fig. 1, and

Figs. :5 and .6 are sketches illustrating alternal he-arirangements tothat shown in Fig. 4.

Throughout, the drawing like parts are given the same references.

Referring to Figs. .1 :and 2 a. recording and transmitting unit IJJ tobe jettisoned comprises recording and. transmitting apparatus I Ilocated within a container I2 .of egg shape. The container I2 ,isprovided with .a shock-absorbing rubber sheath I3 for the purpose ofprotecting the unit when catapulted and when touching down. It isarranged, for example by means of lead I4 fixed in the bottom .of thecontainer I2, that the unit It tends to assume an upright position, asshown in the drawing, when resting upon a level surface. It is alsoarranged that the unit I is buoyant and floats in an upright position.

For the purpose of jettisoning the recording and transmitting unit I0,there is provided "a catapult device comprising a .frame I5 and a pistonI6 mounted to be slidable vertically therein, a1coil-spring I beingdisposed between the Flow-8r surface of the piston it and the base 18 oftheirame I5.

Eeiore the unit II] is placed "in position in the catapult device thepiston 1:6 is :depressed by any suitable means to compress the springI1. when the piston I6 is depressed by a predetermined amount twospring-loaded catches I9 and 2 0 lock it automatically in its depressedposition.

The unit 510. is then loaded into the .catapuit 2 from the top, theupper surface :of the piston 16 containing a depression ZI shaped to fitthe lower, semi-spherical portion of the *unit, and guide surfaces 22being provided in the frame '15 to facilitate loading and ejection ofthe unit II].

parachute pack 23 is fitted to the top of the unit I0 and a parachuterelease pin 24 is connected by means of a steelwvire 25 to the frameI5after the unit 1'0 =is'loaded.

The catches 19 and 20 are released by two electro-magnetic release units26 and 2] respectively which are automatically energised from a battery28 by an inertia-type crash switch 29 which may be located in anyconvenient position in the aircraft.

"When the catches I9 and '20 are released the unit I0 is jettisonedvertically upwards clear of the aircraft by meansoi the piston It andspring I'I. As the unit passes out of the frame I5 the parachute releasepin 24 is automatically withdrawn and the parachute opens ashort timeafter ejection of'the unit I0 takes place.

The unit It includes a telescopic aerial :30 which is attached to theparachute 23.

Fig. 3 illustrates the unit 11! descending by means of the parachute'23. As will be seen the telescopic mast 30 is extended'during thedescent, this being arranged to occur automatically by the pull of theparachute 23. The parachute '23 is attached to the top of the aerial 31]by means of a coupling uni-t -3I, e. g. of the scissorhoo'k type,adapted, after having been loaded, to disengage automatically as aresult of the unit's touching down.

Referring again to Fig. 1, when the unit I-B loaded a connection ismade, by means of a plugand-socket connector 32 and a cable 33, from therecording and transmitting apparatus -II to a navigators microphone 34and a battery 35. The apparatus II contains a battery 46 and drivingmotor 41' (Fig. 4) for use when the unit I-0 is jettisoned. In order toobtain the maximum duration of transmission after ejection, a -portionoi the plug-and-soc'ket connector 32 is arranged, for example as shownin Fig. 4, to disconnect the internal battery when the unit 4,0 isloaded, and to connect the external battery 35 in its place. As shown in'Fig. 4 a movable contact arm 48 is lifted from a fixed contact 49 whenthe plug portion 32" of the connector 32 is inserted into the socketportion 32. In this way the battery 46 is disconnected fromthe motor '41Current is then supplied to "the motor 31 through :the connector 32.Ejection of the unit 10 results in the disconnection of the 'plug fromthe socket in the connector 32 and in the reconnection of the internalbattery 36 to the motor 42'! through the contacts 48 and 49.

During normal flight the navigator records at regular intervalsposition, the time and an adjacent fixed reference point if available.In making these recordings he first of all presses a switch 36associated with his microphone 34. The switch'35 starts the'motor in theapparatus II and applies the necessary voltages to the recording sectionthereof. After each recording the navigator releases the switch 36 andthereby stops the motor and disconnects the battery 35 from therecording apparatus.

Fig. 4 is a diagrammatic sketch of suitable recording apparatus for usein the unit ll] of Figs. 1 to 3. The recording apparatus comprises twomotor-driven reel 37 and 38 around which is passed a single endlessrecord 39 of plastic tape filled 'with magnetic particles. The tape 39.is driven in the direction of the arrow 40 and before it passes througha recording and pick-up-head 4|, information previously recorded thereonis obliterated by means of an obliterating head 42 disposed adjacent therecording head. The length of the tape 39 is arranged to be such that atall times "the latest complete recording is available for transmission,together with a subsequent incomplete recording, if any. In order toensure this in most cases, the tape is preferablymade three times thelength required for one recording of normal duration. When the unit H]is jettisoned the obliterating head is disconnected automatically fromthe circuit, by'the opening of contacts 50 and (Fig. 4), whereby all theinformation contained in the recording tape 39 is transmitted repeatedlyuntil the internal battery 45 is exhausted.

In making the recordings the navigator may preface each report by theinternational S O S signal. Alternatively, if the report signal, as wellas being recorded, is being transmitted immediately as a routine report,theS O S signal may be maintained permanently recorded and arranged inany suitable manner to preface automatically the recorded signals to betransmitte by the unit in an emergency. Y

A manually operable switch 43 (Fig. 1) may be connected in parallel withthe inertia switch 29, whereby the navigator or other member of the crewcan jettison the unit l0 when desired, or in the event of failure of theswitch 29. Other switches, such as wing-tip and nose trip-switches maybe connected to two terminals 44 and 45 and hence in parallel with theswitches 29 and Instead of using a single tape 39 (Fig. 4) two or morerecords may be arranged to co-operate selectively with the recording andobliterating head, in response to the operation of the switch 36, asshown in Fig. 5. The two tapes are shown at 39 and 33' passed around thereel 38 and reel 38 respectively. The reels 38 and 38 are me chanicallyconnected by a tubular member 52 which is internally splined to beslidable on a splined shaft 53. A single pole twor-way switch 54 formingpart of the switch 35 is arranged to apply voltage from the supply 35alternatively to electro-magnets 55 and 56. When the magnet 55 isenergised as shown in the drawing the reels 33 and move to a right-handposition in which the tape 33 co-operates with the obliteratinghead 42and the tape 39' co-operates with the recording and reproducing head 4|.When the magnet 56 is energised the reels'33 and 33' move to a left-handposition where the tape 39 co-operates with an obliterating head 42' andthe tape 39 co-operates with the recording and reproducing head 4|.

, In a further modification, a reel of wire is fixed ill to the base ofthe unit l0 as shown at 51 in Fig. 3 and is released when the unit I0touches down so as to have an anchoring effect in water.

" It may be required tov jettison the unit in the event of a firebreaking out. In this case suitable I. thermal switches of which one isshown at 58"in Fig.1 may be located in suitable positions, for examplejust inside the pilots cabin and near the wing roots. By connecting apair of contacts on each thermal switch to the terminals 44 and iscan bearranged that the unit is jettisoned when any one of the thermalswitches attains a predetermined temperature.

Furthermore an auxiliary record can be left permanently in the unit, andswitched into circuit by additional contacts on the thermal switches asshown in Fig. 6. In this figure the two tapes 39 and 39' co-operaterespectively with the recording and reproducing head 4| and areproducing head 4| respectively. The head 4| is connected in parallelwith the head 4| through contacts and 60 of a relay 6|. This relay isactuated by contacts 32 and 63 of the thermal switch 58. Actuation ofthe relay causes hold-on contacts 64 and to close whereby the relay 6|is kept actuated and hence the head 4| kept in parallel with the head 4|so long as the battery 45 supplies sufficient voltage. The additionalrecord 39 can be adapted to superimpose upon the transmitted signal atpredetermined intervals, e. g. before the commencement of the mainsignal and each repetition thereof, a further signal indicating thatfire has broken out.

I claim: 7

Signal transmitting apparatus adapted'to be carried on an aircrafthaving a general source of electric power and a microphone fittedtherein, said apparatus comprising a frame for attachment to theaircraft, a unit removably mounted in said frame, means for jettisoningsaid unit from said frame, a record, means for recording signals uponsaid record, means for automatically obliterating superseded signalsfrom said record, an internal source of power within said unit, a

radio transmitter for transmitting signals-re- ARUNDELL WALLIS FAULKNER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,022,991 Walter Dec. 3, 19352,149,808 Ellis Mar. 7, 1939 2,310,017 Canon et a1. Feb. 2, 19432,323,064 Lustfield June 29, 1943 2,328,208 Friedman Aug. 31, 19432,402,143 Arenstein June 18, 1946 2,470,783 Mead May 24, 1949 2,473,050Camp June 14, 1949 2,500,809 Fennessy et a]. Mar. 14, 1950

